Synthesis and crystallographic characterization of dimeric perfluoroalkyl iridium complexes: [Cp∗Ir(X)(RF)]2 (X = I, RF = CF3, CF2CF3, CF2CF2CF3, CF(CF3)2, CF(CF3)(CF2CF3); X = Cl and Br, RF = CF2CF3), and a new perfluoroethylidene complex Cp∗Ir(PPh3)(CFC

Monomeric perfluoroalkyl-iridium complexes IrCp∗(RF)(CO)I react with N-methylmorpholine-N-oxide (NMO) with loss of the CO ligand, and clean formation of stable red iodide-bridged dimers, all of which have characterized in solution by 1H and 19F NMR spectroscopy and in the solid state by X-ray diffraction. Dimeric perfluoroethyl analogues with chloro and bromo ligands have also been prepared. Reaction of these iodo-bridged dimers with acetonitrile, ethylene and amines forms the corresponding monomeric complexes in solution but coordination is weak and reversible. CO reacts irreversibly to afford the monomeric starting materials, while PMe3 and PPh3 yield monomeric phosphine complexes, which can be reduced to give perfluoroethylidene compounds.

Graphical abstractAbstraction of CO by NMO followed by addition of phosphine ligands affords a better way to effect overall ligand substitution than direct displacement of CO by PR3; intermediate dimeric complexes are stable and have been fully characterized.Figure optionsDownload full-size imageDownload as PowerPoint slide